Effect of trypsin inhibitor from Crotalaria pallida seeds on  Callosobruchus maculatus (cowpea weevil) and  Ceratitis capitata (fruit fly)

• Published in: Plant physiology and biochemistry Vol. 43; no. 12; pp. 1095 - 1102
• Main Authors: Gomes, Carlos E.M., Barbosa, Aulus E.A.D., Macedo, Leonardo L.P., Pitanga, Joelma C.M., Moura, Fabiano T., Oliveira, Adeliana S., Moura, Raniere M., Queiroz, Alexandre F.S., Macedo, Francisco P., Andrade, Lúcia B.S., Vidal, Márcia S., Sales, Mauricio P.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.12.2005; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Animals; Biological and medical sciences; Callosobruchus maculatus; Ceratitis capitata; Ceratitis capitata - enzymology; Ceratitis capitata - growth & development; Chymotrypsin - antagonists & inhibitors; Crotalaria - chemistry; Crotalaria pallida; Economic plant physiology; Fructification, ripening. Postharvest physiology; Fundamental and applied biological sciences. Psychology; Growth and development; Hydrogen-Ion Concentration; Insecticides - isolation & purification; Larva - enzymology; Lethal Dose 50; Pancreatic Elastase - antagonists & inhibitors; Resistance; Seeds - metabolism; Temperature; Trypsin inhibitor; Trypsin Inhibitors - isolation & purification; Weevils - enzymology; Weevils - growth & development; Crotalaria pallida; Resistance; Ceratitis capitata; Trypsin inhibitor; Callosobruchus maculatus; Cysteine; Seeds; Cysteine endopeptidases; Vigna unguiculata; Dicotyledones; Angiospermae; Aspartic endopeptidases; Inhibition; Serine endopeptidases; Fruit; Enzyme; Crotalaria; Mortality; Papain; Peptidases; Chymotrypsin; Trypsin; Leguminosae; Aspergillopepsin II; Hydrolases; Spermatophyta
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2005.11.004

A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulfate precipitation, affinity chromatography on immobilized trypsin–Sepharose and TCA precipitation. The trypsin inhibitor, named CpaTI, had M r of 32.5 kDa as determined by SDS-PAGE and was composed of two subunits with 27.7 and 5.6 kDa linked by disulfide bridges. CpaTI was stable at 50 °C and lost 40% of activity at 100 °C. CpaTI was also stable from pH 2 to 12 at 37 °C. CpaTI weakly inhibited chymotrypsin and elastase and its inhibition of papain, a cysteine proteinase, were indicative of its bi-functionality. CpaTI inhibited, in different degrees, digestive enzymes from Spodoptera frugiperda, Alabama argillacea, Plodia interpunctella, Anthonomus grandis and Zabrotes subfasciatus guts. In vitro and in vivo susceptibility of Callosobruchus maculatus and Ceratitis capitata to CpaTI was evaluated. C. maculatus and C. capitata enzymes were strongly susceptible, 74.4 ± 15.8% and 100.0 ± 7.3%, respectively, to CpaTI. When CpaTI was added to artificial diets and offered to both insect larvae, the results showed that C. maculatus was more susceptible to CpaTI with an LD 50 of 3.0 and ED 50 of 2.17%. C. capitata larvae were more resistant to CpaTI, in disagreement with the in vitro effects. The larvae were more affected at lower concentrations, causing 27% mortality and 44.4% mass decrease. The action was constant at 2–4% (w/w) with 15% mortality and 38% mass decrease.